Elsewhere, Mello watches Misa, suspecting her to be the second Kira.
But that's not what the show is about, the show is about L the detective vs Light the student , possibly the world's two 2 smartest minds! A high school student named Light Turner discovers a mysterious notebook that has the power to kill anyone whose name is written within its pages, and launches a secret crusade to rid the world of criminals.
With Ryuk establishing at the that he would be the one to sign Light's name in the notebook, it already gave the show an out that made sense.